1. Field of the Invention
The present invention is directed in general to a system using verification/authentication of Personal Identification Signal for banking, security and charge card transactions, and more particularly to a system which employs a low-capacity portable memory device to store set of features and parameters extracted from a Signal template. Said parameters are used to simplify processing incoming Signal, while said features are for verification/authentication of incoming Signal by the system.
2. Description of the Background Art
Personal Identification Number (PIN) is widely used in automatic teller machines, and in many other security devices where only authorized users are allowed to perform selective actions. However, PIN has some disadvantages, and these become very inconvenient for the users. This is because:
PIN usually contains many digits which can be easily forgotten PA1 disclosed PIN can be used (and misused) by any unauthorized person PA1 when special equipment is used, PIN can be directly read from a memory device (e.g. from magnetic cards) by an unauthorized person. PA1 (a) proposing a Personalized Identification Signal (PIS) concept, wherein PIS is an easily repeatable hand-written contour which is different from a person's signature used for signing documents; PA1 (b) creating a description of a PIS template, wherein the description consists of selective parameters representing results of segmentation of the PIS template, and of selective feature measurements characterizing strokes created by said segmentation; PA1 (c) memorizing said description of a PIS template using low-capacity portable memory device; PA1 (d) using parameter-controlled segmentation algorithms to process incoming Signal and then to compute features for the segmented incoming Signal in order to compare said features with the feature measurements of the PIS template to decide whether or not the incoming Signal can be accepted, wherein said parameters and feature measurements are retrieved from said portable memory device furnished by a customer.
The overall performance of the systems could be significantly enhanced if PIN is substituted/supplemented by Personalized Identification Signal (PIS) which does not have to be the original signature of a person. It is recommended that PIS would actually be any hand-drawn contour picture which is easily repeatable and can be easily memorized. Nevertheless, a system utilizing a PIS concept should be equipped with a signature verification module although the complexity of the module could be significantly reduced.
Most of the already proposed systems for automatic recognition (verification, authentication) of hand-written signatures utilize the dynamic description of contour images, where both the position (horizontal and vertical coordinates) and the motion (time-domain coordinates) of the tip a drawing device (stylus) are sensed and memorized.
The dynamic description of signatures have been addressed by numerous practitioners including, for example, U.S. Pat. No. 5,111,512, issued to Fan et al. on May 5, 1992, U.S. Pat. No. 4,607,386, issued to Morita et al. on Aug. 19, 1986, U.S. Pat. No. 5,054,088, issued to Gunderson et al. on Oct. 01, 1991, U.S. Pat. No.5,101,437, issued to Plamondon on Mar. 31, 1992, and U.S. Pat. No. 4,495,644, issued to Parks et al. on Jan. 22, 1985. Usually, in the systems of automatic verification/authentication of personal signatures, the dynamic description is used to perform segmentation of an incoming signature, i.e. to extract a sequence of strokes from said signature. Then, the feature-based description of said signature is created, i.e. the signature is represented by a sequence of values characterizing selective properties of the extracted strokes and of the whole signature. The number of utilized features can be significantly large. For example, Parks et al. in U.S. Pat. No. 4,495,644 disclose 93 features useful in the analysis of a signature. Moreover, the nature of features utilized is very diversified. They include features directly describing shapes of signatures (spatial and time-domain coordinates of the contour) as well as features characterizing the drawing process (profiles of velocity, acceleration and pressure of the stylus).
In a verification system, the feature-based description of an incoming signature is compared with the feature-based description of the signature template to decide whether or not the incoming signature can be accepted. The signature template description can be either retrieved form a database containing templates of all the eligible users, or can be furnished by a customer (using a portable memory device).
The first approach is described, for example, by Parks et al. in U.S. Pat. No. 4,495,644. However, a typical signature verification/authentication system consists of many autonomous verification units (e.g. ATM machines, security check points) which have only limited access or no access at all to the central unit (e.g. the mainframe computer of a banking system). Obviously, the verification units would not have any database containing signature templates for all the eligible customers.
The second approach is reported, for example, by Gunderson et al. in U.S. Pat. No. 5,054,088, and by Haraguchi in U.S. Pat. No. 5,150,420. However, such approach may require extensive memory capacity due to the requirement for storing the entire physical data of the template and/or complex feature-based description of the template. The existing systems of magnetic cards or similar portable memory devices have too limited memory capacities to incorporate this option.
Moreover, the verification units are usually equipped with inexpensive computing devices only. Therefore, the algorithms of signature verification are either too complex to incorporate in the verification units, or the reliability of these algorithms becomes too limited. This is first because of the number and complexity of features, and secondly because segmentation algorithms require complex mathematical operation of incoming signatures in order to determine the appropriate number of extracted strokes and their location within the signature.
As a result, the present system methods to date impose severe limitations and significant disadvantages for practical implementation. It would therefore be highly desirable to further propose novel system method with particular technological innovations for the dynamic processing, verification and authentication of binary contour image. This will lead towards the improvement of the overall system operation efficiency and productivity for the computerized banking, security, charge card transaction, and/or related industries.